Electric furnace.



J. THOMSON. l ELECTRIC FUNAGE, APPLICATION FILED SEPT. 1, 1909.

Patented Mar. 1. 1910.

Swim/w f M,

confined, under NEEN THGMSON', 0F NEN YORK, N.

To all whom it may concern:

Be 1t lniovvn that Jenn Triorrson, a citizen ot the United States, 'and a resident of the borough of Manhattan Nerv York, in the county and State of New York, have invented certain improvements in the following being had forming a part hereof.

In electric furnaces, in which the thermal element is a resister formed of regularly such as carbon blocks, .the resister will deformation when it kbecomes by the current, such deformation destroying the uniformity of contact between the sevshaped pieces, happens that eral elements of the resister ing the current density between different and obviously destroying the uniform development and radiation of heat from the resister as a whole.

portions of the resister,

This is particularly so Wh element consists of an arched resister, for in such a case the arch when heated will rise if the yfaces of the tutinggthe arch are primarily in uniform Contact along` its crown, and blocks or members consti up at the upper surface of becoming heated, and the The object of the present provide means, either automatic or manual, for compensating the deformation which place inv an electric resister, under the Whether the resister. anvarch or in some inwhich a deformation is liable to take place due to thermal changes. the dra\\ fings,-Figdre l is takes conditions referred to, be built in the form of other form Referring to., a to plan vicW., with the co an e ectric furnace embodying the invention,

and Fig. 2 is a longitudinal the sectional line 2-2 in Fig. 1.

ln the present case, to illustrate the application of the invention,

resister D, D', is shown spa ingchamber c, the brick-Work and having a lining c and a ing u. lfhe resister arches a each case by the radial or their extremities. i

Electric Furnaces, of which is a specification, reference to 'the accompanying drawings,

such circumstances, to the lower or under surface of the arch.

plane being indicated by the the latter being formed by a, inclosed by the ELECTEIC i #survivre raster f im -risanare @le reien,

'EURE'.

FRNACE.

Specification of Letters Estant..

application tiled September w09.

txatented Man E., serial no, 515,702.

of the city of new and useful it often undergo highly heated and thus varyen the thermal.

tlr'ey will open the, arch, upon current will be invention is to Ver removed, of.

central section,

a double arch nning the meltcover 7), charging openre supported in face contact of tuting the arches were regularly formed prismatic blocks in uniform Contact with each other and it the rested upon' unyielding arches would become deformed or distorted by rising along their crowns, when suffi! ciently heated, with the result that the blocks or elements of the resister would separate along the top surface thereof. More over, as in any such torni of arch, `the lineari length along its upper surface is ,greater than that along its inner surface, the current density, when such arch is used as a supports, then the of construction, will primarily be the greater at the inner surface; and this condition will be augmented in the ratio of et' the arch and separation of the con-- tacts. of carbon is required to safely carry a given quantity `oit energy in given period ot time, such a structure does not meet the require ments in that its transmitting sectioifis e maximum at low temperature and a minio mum at high.

members l 'constituting the arches vare formed so that when primarily set, the lower portions of their faces will not be in physical contact, as shown in Fig. 52,.v The conu sequence of this is that when the arch is heated, and expands and rises, say as indi cated by the broken line m, the lower porphysical contact and the entire mass of the trically.

The required amount of clearance between the lower portions of the faces of the blocks canbe easily determined where any standard manufacture of amorphous carbon is used, Whose average coefficient of expansion and contraction Within given temperatures has been ascertained with suticient accuracy; or, in any event, the required amount of clearance canbe sufficiently approximated by practical demonstration.

been considered as being entirely free at their crowns and supported upon unyielding terminals or other pieces. ln the drawings,

two arches are shown to con- 'iponnd resister the ends of igen connectors c2 and the PRCCESE CJLPANY, OE

- New, if the elements or members constiends o the arches4 resister, even under good normal conditions the deformation l ndob'viously, When 'a given seetrien v To obviate the foregoing,` objectionfthe) tions ot' the blocks o? will be forced into L,

resister will be in approximate balance elec in the foregoing, the arch or arches have .leiter being` supported by the briclmvor.; the furnace. The eiinimils e and c ha. innei` ni'ch-blocl sectie-,is cand e", which may 3e considered as the keystenes of the arches respectively. In this wise, the deformation is nime uniformly elisiibuicd over a gre-aten p01 n of ilse miens (nete the breken lines 92, 'l @han ii? le centers 'were free, loieover, this' afield.' iclclitiensl means of conipensziiion, by Slightly withdrawing the keystone. eminsls; and. the latei may also be utilizeei fel' forcing the ineinbeis of the resistexog'ehei'.

The clistoiien of the zu'ch may be furthe?? compensated :for by resting the connectors 32 and c3 against suitable refiaeoiies a', extending out tiiough the biickeii'oiflf; to he manipuhiecl by an. operaio? ei' to yield against s esilient resistance (nel: shewn).

It will be understood from die foregoing description how the ii ventien may be ein* bodied in` other l'ciins oit' elec'u il uinrfnvs. und is izo be Qniticulai". mined i'hit. ille iniprei enieni'" we not li he spe-clin fel i of shown 'i claim as my i3 7e-Miei hiatiozi 'under lient the urea of Contact bciliveen the blocks 'will increase.

ln in electric furnace, a curved resister Composed of a pluialiihy oi members,the lower poriions of their side faces being prinmrily out of Contact with each other.

.ln an electric furnace, a curved resister coinposerl ef e plurality of members, the lewei portiens ef their side faces being primarily out of Contact with each other and ughtlinte physieiil Contact by thermal deformation of themesister.

mi electric furnace having n` curved esister, conducting pieces upon which its enfis are, supported, and adjustable i'eiiue- 'oi'ics extending to 'the exterior of the furnace upon which said pieces liest -.n electric 'furnace having a curved resister the elements oi" 'which :ire blocks nzii'i'ewci n( one end than atihe other and which blocks :1re :irrangenl'so that the opposing' faces :it (he nari-miei' ends we out of coninei wih euch other.

This specilieulieu signed nml witnessed ihis Elst (hay of August, l), "i909,

Signed in the presence el? [i m Li N s, sie GRAN n 

